Analysis of bitter compounds in traditional preparations of Gentiana purpurea L

Roots of Gentiana purpurea are known to have an intense bitter taste due to its high content of secoiridoids. In folk medicine roots have commonly been prepared as water decoctions, soaked in ethanol, or boiled with milk, wine, or beer. The aim of this study was to explore how various historical preparation methods influence yields of major bitter compounds in G. purpurea. HPLC-DAD analysis revealed that maceration with 40% and 70% ethanol, boiling with acetic acid (3% and 6%), vinegar and raw milk gave the highest extraction yields of gentiopicrin. Erythrocentaurin was detected when the roots were added to cold water before boiling, possibly because of enzymatic degradation. In contrast, erythrocentaurin was not detected in preparations where roots were added to boiling water, or when they were extracted with acetic acid or alcohol. The results stress the significance of traditional preparation methods to optimize yield of bioactive compounds.

Investigating the mechanism and efficacy material basis of Xiehuo Xiaoying decoction for treating Graves' disease via thyroid cell apoptosis based on proteomics and molecular docking techniques

ETHNOPHARMACOLOGICAL RELEVANCE

For numerous years, the Xiehuo Xiaoying decoction (XHXY), a traditional Chinese medicine formula, has demonstrated substantial promise in treating Graves' disease (GD) in clinical settings, showcasing significant potential. However, the therapeutic mechanism and efficacy material basis of XHXY remains obscure.

AIM OF THE STUDY

This work aims to investigate the underlying mechanisms and to study the efficacy material basis of XHXY in anti-GD effect using a combination of TMT quantitative proteomics and molecular docking method.

MATERIALS AND METHODS

GD model was initiated by administering Ad-TSH289. Subsequently, the mice underwent a four-week regimen that included oral gavage of XHXY at doses of 17 g/kg·d and 34 g/kg·d, along with intraperitoneal injections of Gentiopicroside (GPS). Utilizing the principles of pharmacological chemistry in traditional Chinese medicine, we employed high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS) to discern prescribed prototype composition of XHXY in serum samples from mouse. TMT proteomics research provided evidence of XHXY's putative targets and important pathways in vivo. The binding activity of probable action targets and prototype composition was detected by molecular docking. Finally, Immunohistochemistry (IHC) and TUNEL staining were used to verify the mechanism of XHXY and GPS in anti-GD.

RESULTS

XHXY and GPS alleviated GD by ameliorating the pathological changes and reducing thyroxine and TRAb levels. In mouse serum, a total of 31 prototypical XHXY ingredients were detected, and the majority of these components were from monarch and minister medicine. Proteomics study results indicated that the XHXY may mainly regulate targets including FAS-associated death domain protein (FADD), Apolipoprotein C-III, etc. and main pathways are Apoptosis, Cholesterol metabolism, TNF signalling pathway, etc. Strong binding activity of the prototypical active ingredient and GPS towards FADD, Caspase 8, and Caspase 3 was demonstrated by molecular docking. XHXY and its primary component, GPS, elevated the expression of FADD, Caspase 8, and Caspase 3, and enhance apoptosis in thyroid cells, as lastly validated by TUNEL and IHC staining.

CONCLUSIONS

XHXY exhibits a favorable therapeutic effect in treating GD by promoting apoptosis in thyroid cells through the upregulation of FADD, Caspase 8, and Caspase 3 expression. And GPS is the main efficacy material basis for its therapeutic effect in anti-GD.

Gentiopicroside ameliorates the lipopolysaccharide-induced inflammatory response and hypertrophy in chondrocytes

PURPOSE

This study aimed to evaluate the protective effects of gentiopicroside against lipopolysaccharide-induced chondrocyte inflammation.

METHODS

SW 1353 chondrosarcoma cells were stimulated with LPS (5 μg/ml) for 24 h and treated with different concentrations of gentiopicroside (GPS) for 24 h. The toxic effects of GPS on chondrocytes were determined using a CCK-8 assay and EdU staining. Western blotting, qPCR, and immunofluorescence analysis were used to examine the protective effect of GPS against the inflammatory response in chondrocytes induced by lipopolysaccharide (LPS). One-way ANOVA was used to compare the differences between the groups (significance level of 0.05).

RESULTS

The CCK-8 results showed that 10, 20 and 40 μM GPS had no significant toxic effects on chondrocytes; GPS effectively reduced the production of IL-1β and PGE2, reversed LPS-induced extracellular matrix degradation in cartilage by inhibiting the Stat3/Runx2 signaling pathway, and suppressed the hypertrophic transformation of SW 1353 chondrosarcoma cells.

CONCLUSION

Our study demonstrated that GPS significantly inhibited the LPS-induced inflammatory response and hypertrophic cellular degeneration in SW 1353 chondrosarcoma cells and is a valuable traditional Chinese medicine for the treatment of knee osteoarthritis.

Study of the mechanism by gentiopicroside protects against skin fibroblast glycation damage via the RAGE pathway

The occurrence of nonenzymatic glycosylation reactions in skin fibroblasts can lead to severe impairment of skin health. To investigate the protective effects of the major functional ingredient from Gentianaceae, gentiopicroside (GPS) on fibroblasts, network pharmacology was used to analyse the potential pathways and targets underlying the effects of GPS on skin. At the biochemical and cellular levels, we examined the inhibitory effect of GPS on AGEs, the regulation by GPS of key ECM proteins and vimentin, the damage caused by GPS to the mitochondrial membrane potential and the modulation by GPS of inflammatory factors such as matrix metalloproteinases (MMP-2, MMP-9), reactive oxygen species (ROS), and IL-6 via the RAGE/NF-κB pathway. The results showed that GPS can inhibit AGE-induced damage to the dermis via multiple pathways. The results of biochemical and cellular experiments showed that GPS can strongly inhibit AGE production. Conversely, GPS can block AGE-induced oxidative stress and inflammatory responses in skin cells by disrupting AGE-RAGE signalling, maintain the balance of ECM synthesis and catabolism, and alleviate AGE-induced dysfunctions in cellular behaviour. This study provides a theoretical basis for the use of GPS as an AGE inhibitor to improve skin health and alleviate the damage caused by glycosylation, showing its potential application value in the field of skin care.

Gentiopicroside inhibits retinoblastoma cell proliferation, invasion, and tumorigenesis in nude mice by suppressing the PI3K/AKT pathway

Retinoblastoma is a prevalent pediatric intraocular tumor. The suppressive effect of gentiopicroside (GPS) has been reported on various tumors. This study sought to determine the effect of GPS on retinoblastoma cell proliferation, apoptosis, invasion, and epithelial-mesenchymal transition (EMT), and tumorigenesis in nude mice. The effect and mechanism of GPS on growth, apoptosis, invasion, and EMT were determined by cell counting kit-8 (CCK-8), western blot, flow cytometry, and transwell assays in retinoblastoma cells. Y79 cells were injected into the vitreous cavity of BALB/c‑nude mice to construct a retinoblastoma mouse model. Tumor growth and mouse weight were monitored for sequential 5 weeks. The effect of GPS in vivo was assessed by immunohistochemistry (IHC), terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), and western blot assays. GPS decreased the cell viability of both Y79 and Weri-Rb1 cells with the IC50 of 18.85 μM and 27.57 μM, respectively. Besides, GPS reduced the relative expression of proteins involved in proliferation and EMT, and the number of invading cells, while increased the apoptosis rate and the relative expressions of apoptosis proteins in retinoblastoma cells. Mechanically, GPS decreased the relative protein level of PI3K/AKT pathway, which was then recovered after 740 Y-P was applied. Correspondingly, 740 Y-P reversed the inhibitory effect of GPS on growth, invasion, and EMT, and the increased effect of GPS on apoptosis. Additionally, GPS decreased tumor volume and weight as well as the relative level of Ki-67, VEGF, p-PI3K/PI3K, and p-AKT/AKT, while increased the apoptosis rate in vivo. GPS inhibited retinoblastoma cell proliferation and invasion via deactivating the PI3K/AKT pathway in both cell and animal models.

Regulatory mechanisms of Gentiopicroside on human diseases: a brief review

Gentiopicroside (GPS), a single compound isolated from Gentiana lutea L. and the crucial representative of secoiridoid constituent, has been permitted for centuries in traditional Chinese medicine. GPS and its metabolites have been increasingly used in the search for clinical management with therapeutic properties and fewer side effects. The objective of this review was to provide a comprehensive overview of the involvement of molecular pathways in the therapeutic effects of GPS on human diseases and chronic conditions. This study presents a meticulously conducted comprehensive search of the PubMed and Google Scholar databases (from 1983 to 2023), aimed at identifying articles relating to regulatory mechanisms of GPS on human diseases and the pharmacokinetics of GPS. The inclusion criteria were meticulously and precisely defined to encompass original research papers that explicitly focused on elucidating the regulatory mechanisms of GPS in various human diseases through in vitro and animal studies. Notably, these studies were mandated to integrate specific genetic markers or pathways as essential components of their research inquiries. The evaluated pharmacokinetic parameters included maximum plasma concentration (Cmax), time to reach maximum plasma concentration (Tmax), area under the curve (AUC), clearance, and plasma half-life (t1/2). Subsequently, through a rigorous screening process of titles and abstracts, studies conducted in vitro or on animals, as well as those reporting pharmacokinetic data related to drugs other than GPS or language barriers, were systematically excluded. Drawing from the data and studies pertaining to this review, we conducted a thorough and informative analysis of the pharmacological characteristics and biological functions of GPS. These encompassed a wide range of effects, including hepatoprotective, anti-inflammatory, antifibrotic, antioxidant, analgesic, antitumor, and immunomodulatory properties. The analysis provided a comprehensive and insightful understanding of GPS's pharmacological profile and its diverse activities. Enhancing theoretical and experimental methodologies could prove advantageous in expanding the clinical applications of GPS. This could involve optimizing the bioavailability and pharmacokinetics of GPS, uncovering additional biomarkers and potential biotransformation pathways, and investigating its combined effects with standard-of-care medications.

Gentiopicroside inhibits the progression of gastric cancer through modulating EGFR/PI3K/AKT signaling pathway

BACKGROUND

This study was designed to clarify the function and potential mechanism of gentiopicroside (GPS) in regulating the malignant progression of gastric cancer (GC) through in vitro cellular experiments and in vivo animal models.

METHODS

AGS and HGC27 cells were divided into control group and GPS treatment groups (50 µM and 100 µM). Then, the cellular proliferation, colony formation, migration, invasion, and apoptosis were detected, respectively. Transmission electron microscope (TEM) was used to observe the mitochondrial changes, and the mitochondrial membrane potential (MMP) was determined using the JC-1 commercial kit. Network pharmacology analysis was utilized to screen the potential molecule that may be related to the GPS activity on GC cells, followed by validation tests using Western blot in the presence of specific activator. In addition, xenografted tumor model was established using BALB/c nude mice via subcutaneous injection of HGC27 cells, along with pulmonary metastasis model. Then, the potential effects of GPS on the tumor growth and metastasis were detected by immunohistochemistry (IHC) and HE staining.

RESULTS

GPS inhibited the proliferation, invasion and migration of GC cell lines in a dose-dependent manner. Besides, it could induce mitochondrial apoptosis. Epidermal growth factor receptor (EGFR) may be a potential target for GPS action in GC by network pharmacological analysis. GPS inhibits activation of the EGFR/PI3K/AKT axis by reducing EGFR expression. In vivo experiments indicated that GPS induced significant decrease in tumor volume, and it also inhibited the pulmonary metastasis. For the safety concerns, GPS caused no obvious toxicities to the heart, liver, spleen, lung and kidney tissues. IHC staining confirmed GPS downregulated the activity of EGFR/PI3K/AKT.

CONCLUSIONS

Our investigation demonstrated for the first time that GPS could inhibit GC malignant progression by targeting the EGFR/PI3K/AKT signaling pathway. This study indicated that GPS may be serve as a safe anti-tumor drug for further treatment of GC.

Gentiopicroside Ameliorated Ductular Reaction and Inflammatory Response in DDC-induced Murine Cholangiopathies Model

BACKGROUND

Cholangiopathies comprise a spectrum of diseases without curative treatments. Pharmacological treatments based on bile acid (BA) metabolism regulation represent promising therapeutic strategies for the treatment of cholangiopathies. Gentiopicroside (GPS), derived from the Chinese medicinal herb Gentianae Radix, exerts pharmacological effects on bile acid metabolism regulation and oxidative stress.

OBJECTIVE

The present study aims to investigate the effect of GPS on 3,5-diethoxycarbonyl-1,4dihydrocollidine (DDC)-induced cholangiopathy.

METHODS

Two independent animal experiments were designed to evaluate the comprehensive effect of GPS on chronic DDC diet-induced cholangiopathy, including bile duct obliteration, ductular reaction, BA metabolism reprogramming, liver fibrosis, oxidative stress and inflammatory responses.

RESULTS

In the first pharmacological experiment, three doses of GPS (5, 25 and 125 mg/kg) were injected intraperitoneally into mice fed a DDC diet for 14 days. DDC induced a typical ductular reaction, increased periductal fibrosis and mixed inflammatory cell infiltration in the portal areas. GPS treatment showed dose-dependent improvements in the ductular reaction, BA metabolism, fibrosis, oxidative stress and inflammatory response. In the second experiment, a high dose of GPS was injected intraperitoneally into control mice for 28 days, resulting in no obvious histologic changes and significant serologic abnormalities in liver function. However, GPS inhibited DDC-induced oxidative stress, serum and hepatic BA accumulation, proinflammatory cytokine production, and immunocyte infiltration. Specifically, the GPS-treated groups showed decreased infiltration of monocyte-derived macrophages and CD4+ and CD8+ T lymphocytes, as well as preserved Kupffer cells.

CONCLUSION

GPS alleviated chronic DDC diet-induced cholangiopathy disorder by improving the ductular reaction, periductal fibrosis, oxidative stress and inflammatory response. Its dosage-dependent pharmacological effects indicated that GPS warrants its further evaluation in clinical trials for cholangiopathy.

Gentiopicroside improves high-fat diet-induced NAFLD in association with modulation of host serum metabolome and gut microbiome in mice

Objective

The incidence of non-alcoholic fatty liver disease is increasing every year, and there is growing evidence that metabolites and intestinal bacteria play a causal role in NAFLD. Gentiopicroside, a major iridoids compound in gentian, has been reported to reduce hepatic lipid accumulation. However to date, no studies have confirmed whether the predominance of Gentiopicroside is related to metabolites and intestinal bacteria. Therefore, we sought to study whether the hypolipidemic effect of Gentiopicroside is related to metabolic function and intestinal flora regulation.

Methods

In the present study, C57BL/6J mice were fed a high-fat diet for 12 weeks, followed by a high-fat diet with or without Gentiopicroside for 8 weeks, respectively. The Gentiopicroside intervention reduced body weight gain, liver index, and decreased serum biochemical parameters such as alanine aminotransferase, aspartate aminotransferase, and triglycerides in high-fat fed mice. The effect of Gentiopicroside on non-alcoholic fatty liver disease was studied using serum untargeted metabolomics and 16S rDNA assay.

Results

Metabolomic analysis showed that the addition of Gentiopicroside significantly altered the levels of amino acids, unmetabolized Gentiopicroside after administration, and metabolites such as Cinnoline, Galabiosylceramide, and Tryptophyl-Tyrosine, which are involved in the pathways regulating bile secretion, tryptophan metabolism, and lipid metabolism. Analysis of intestinal bacteria showed that Gentiopicrosides altered the community composition structure of intestinal bacteria, characterized by an increase and a decrease in beneficial and harmful bacteria, respectively. In addition, correlation analysis showed that the effect of Gentiopicroside on metabolites was positively correlated with intestinal flora Bacteroides, Lactobacillus, Muribaculum, and Prevotellaceae_UCG_001. Finally, the combined analysis revealed that metabolites were associated with the regulation of Firmicutes and Actinobacteria and positively correlated with lipid levels.

Conclusion

These results suggest that Gentiopicroside may be a potential agent for the prevention of intestinal disorders and the alleviation of non-alcoholic fatty liver disease.

Determination of lead in Gentiana rigescens and evaluation of the effect of lead exposure on the liver protection of the natural medicine

In this work, ultrasound-assisted rapidly synergistic cloud point extraction (UARS-CPE) and inductively coupled plasma optical emission spectrometry (ICP-OES) were combined to determine trace Pb in Gentiana rigescens Franch. ex Hemsl. (G. rigescens) samples. Under the optimal conditions, the enhancement factor (EF), limit of detection (LOD), limit of quantitation (LOQ) and precision were 33, 0.11 μg L^-1, 0.37 μg L^-1 and 1.3%, respectively. This method was applied to the analysis of G. rigescens samples, and the outcomes were in good agreement with the results determined by inductively coupled plasma mass spectrometry (ICP-MS). A mice model of immune liver injury induced by concanavalin A (ConA) was established, and the liver protection of G. rigescens and gentiopicroside (GPS) on it and the effects of various dosages of Pb exposure on its liver protection were studied. Pb at a dosage of 5 mg kg^-1 had little effect on the liver protection of G. rigescens and GPS, while 25, 125 mg kg^-1 dosages of Pb could significantly attenuate the liver protection of both. In addition, it aggravated the necrosis of hepatocytes and inflammatory cell infiltration, and these effects were dose-dependent.

Gentiopicroside alleviated epileptogenesis in immature rats through inactivation of NLRP3 inflammasome by inhibiting P2X7R expression

OBJECTIVES

This study aimed to elucidate the effects of Gentiopicroside (Gent) on epileptogenesis and underlying mechanisms.

METHODS

The status epilepticus (SE) model was established by intraperitoneal (i.p.) injection of lithium chloride (127 mg/kg) and pilocarpine (50 mg/kg) in immature rats. HAPI microglial cellular inflammation model was induced by lipopolysaccharide (LPS, 1 μg/ml) and adenosine triphosphate (ATP, 5 mM). The differential concentrations of Gent were used to pretreat animal (200, 400, and 800 mg/kg) and model cells (50, 100, and 200 μM). Epileptic discharges were assessed by electroencephalography (EEG) and Racine scale. Changes in spatial memory function were measured using the Morris water maze task test. Nissl and FJB staining were employed to assess the damage to hippocampus tissues. ELISA was used to detect the production of IL-1β, IL-18, and TNF-α. The expressions of P2X7R and NLRP3 were detected by q-PCR, immunofluorescence staining, and Western blot, and cell viability was determined by cell counting kit-8 (CCK-8).

RESULTS

Lithium chloride and pilocarpine (LICL-PILO) induced abnormal EEG activities, behavioral alterations, brain damage, and inflammatory responses in immature rats. However, Gent pretreatment significantly reduced the neuronal damage and spatial memory dysfunction induced by LICL-PILO. Additionally, Gent suppressed the production of inflammatory cytokines and inhibited the expression of P2X7R, NLRP3, ASC, and Caspase-1 in LPS/ATP-induced HAPI microglial cells.

DISCUSSION

Gent intervention could improve epileptogenesis in immature rats partially due to suppressing P2X7R and NLRP3 inflammasome.

(±)-Gentiovarisin A and gentiovarisin B, unusual secoiridoid dimer skeletons from gentiopicroside

Gentiana scabra, a famous traditional Chinese medicine (TCM), has been documented in Chinese Pharmacopoeia for the treatment of hepatitis. Its index component gentiopicroside could not be detected in the decoction, which suggested that the quality control of the TCM with this ingredient needs attention. The transformed products were obtained from gentiopicroside, mimicking the traditional process of G. scabra. Further investigation of the heat-transformed products yielded two secoiridoid dimers, gentiovarisin A (1) and B (2), with an unprecedented 6/6/6/6/6-fused pentacyclic skeletons. Their structures were elucidated by extensive spectroscopic analyses and single-crystal X-ray diffraction analysis, and the absolute configurations of 1 were confirmed as (+)-1 and (-)-1 by ECD method. Plausible transformation pathways of the isolates were also proposed. Compounds 1 and 2 exhibited in vitro hepatoprotective activity similar to gentiopicroside, while (+)-1 displayed a more potent hepatoprotective activity than N-Acetyl-L-cysteine.

Gentiopicroside alleviates cardiac inflammation and fibrosis in T2DM rats through targeting Smad3 phosphorylation

BACKGROUND

Cardiac fibrosis is a major structural change observed in the heart of patients with type 2 diabetes mellitus (T2DM), ultimately resulting in heart failure (HF). Suppression of inflammation is an effective therapeutic strategy for treating cardiac fibrosis and HF. Gentiopicroside (GPS), the primary component of Gentiana manshurica Kitagawa, possess potent anti-inflammatory activity. However, its cardioprotective role remains elusive.

PURPOSE

We explored the potential cardioprotective role of GPS in T2DM rats and its underlying mechanisms.

METHODS

T2DM rats built by high-fat diet and streptozotocin were orally administered 25, 50, or 100 mg/kg GPS, daily for 8 weeks. The positive control drug was Metformin (200 mg/kg/day). Primary cardiac fibroblasts (CFs) were induced by high glucose (30 mM) and subsequently treated with GPS (100 μM). Cardiac function and pathological changes were analyzed using echocardiography and histological staining. Potential targets of GPS were predicted using Molecular docking. Real-time PCR as well as western blotting were applied to verify the expression of objective genes.

RESULTS

All three doses reduced fasting blood glucose levels, but only 50 and 100 mg/kg GPS improved cardiac function and alleviated inflammation and fibrosis in T2DM rats. GPS (100 mg/kg) exhibited a better effect, similar to that of metformin. Mechanistically, binding between GPS and the MH2 domain of Smad3 blocked high glucose-induced Smad3 phosphorylation, thus attenuating inflammation, oxidative stress, and activation in CFs.

CONCLUSION

We, for the first time, demonstrated that GPS improved cardiac function in T2DM rats and elucidated the underlying mechanism through which GPS targeted Smad3 phosphorylation to suppress inflammation and activation in CFs, thereby revealing the potential application of GPS in HF therapy.

Gentiopicroside targets PAQR3 to activate the PI3K/AKT signaling pathway and ameliorate disordered glucose and lipid metabolism

The obstruction of post-insulin receptor signaling is the main mechanism of insulin-resistant diabetes. Progestin and adipoQ receptor 3 (PAQR3), a key regulator of inflammation and metabolism, can negatively regulate the PI3K/AKT signaling pathway. Here, we report that gentiopicroside (GPS), the main bioactive secoiridoid glycoside of Gentiana manshurica Kitagawa, decreased lipid synthesis and increased glucose utilization in palmitic acid (PA) treated HepG2 cells. Additionally, GPS improved glycolipid metabolism in streptozotocin (STZ) treated high-fat diet (HFD)-induced diabetic mice. Our findings revealed that GPS promoted the activation of the PI3K/AKT axis by facilitating DNA-binding protein 2 (DDB2)-mediated PAQR3 ubiquitinated degradation. Moreover, results of surface plasmon resonance (SPR), microscale thermophoresis (MST) and thermal shift assay (TSA) indicated that GPS directly binds to PAQR3. Results of molecular docking and cellular thermal shift assay (CETSA) revealed that GPS directly bound to the amino acids of the PAQR3 NH₂-terminus including Leu40, Asp42, Glu69, Tyr125 and Ser129, and spatially inhibited the interaction between PAQR3 and the PI3K catalytic subunit (P110α) to restore the PI3K/AKT signaling pathway. In summary, our study identified GPS, which inhibits PAQR3 expression and directly targets PAQR3 to restore insulin signaling pathway, as a potential drug candidate for the treatment of diabetes.

Gentiopicroside promotes the osteogenesis of bone mesenchymal stem cells by modulation of β-catenin-BMP2 signalling pathway

Osteoporosis is characterized by increased bone fragility, and the drugs used at present to treat osteoporosis can cause adverse reactions. Gentiopicroside (GEN), a class of natural compounds with numerous biological activities such as anti‐resorptive properties and protective effects against bone loss. Therefore, the aim of this work was to explore the effect of GEN on bone mesenchymal stem cells (BMSCs) osteogenesis for a potential osteoporosis therapy. In vitro, BMSCs were exposed to GEN at different doses for 2 weeks, whereas in vivo, ovariectomized osteoporosis was established in mice and the therapeutic effect of GEN was evaluated for 3 months. Our results in vitro showed that GEN promoted the activity of alkaline phosphatase, increased the calcified nodules in BMSCs and up‐regulated the osteogenic factors (Runx2, OSX, OCN, OPN and BMP2). In vivo, GEN promoted the expression of Runx2, OCN and BMP2, increased the level of osteogenic parameters, and accelerated the osteogenesis of BMSCs by activating the BMP pathway and Wnt/β‐catenin pathway, effect that was inhibited using the BMP inhibitor Noggin and Wnt/β‐catenin inhibitor DKK1. Silencing the β‐catenin gene and BMP2 gene blocked the osteogenic differentiation induced by GEN in BMSCs. This block was also observed when only β‐catenin was silenced, although the knockout of BMP2 did not affect β‐catenin expression induced by GEN. Therefore, GEN promotes BMSC osteogenesis by regulating β‐catenin‐BMP signalling, providing a novel strategy in the treatment of osteoporosis.

Effects of Gentiopicroside on activation of NLRP3 inflammasome in acute gouty arthritis mice induced by MSU

Acute gouty arthritis is a self-limiting inflammatory disease resulting from the deposition of monosodium urate (MSU) crystals. It has been shown that Gentiopicroside (GPS) possesses anti-inflammatory and analgesic functions. The aim of this study was to parse out whether GPS has an effect on acute gouty arthritis. We established an acute gouty arthritis model by the injection of MSU into the paw, and found that GPS relieves MSU-induced mechanical, thermal hyperalgesia, and paw swelling. Furthermore, GPS down-regulated the release of pro-inflammatory cytokines in paw tissues, including IL-1β, IL-6, IL-18, and TNF-α. The results of H&E staining and MPO activity measurement showed that GPS inhibits neutrophil infiltration. And the over-expressions of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and Caspase-1 induced by MSU were inhibited by treatment with GPS. These results revealed that GPS can treat acute gouty arthritis based on anti-inflammatory and analgesic properties in vivo, which might be ascribed to the inhibition on NLRP3 inflammasome. Furthermore, we performed in vitro study to confirm the results of in vivo study. Consistently, the results proved that GPS could inhibit the activation of NLRP3 inflammasome in RAW264.7 macrophages stimulated by LPS-MSU. In conclusion, this study provides an experimental basis for the application of GPS and expands the potential value of GPS in the therapy of acute gouty arthritis.

Gentiopicroside inhibits proliferation, migration, and invasion of gastric cancer HGC-27 cells by regulating miR-34c-5p/XBP1 axis

BACKGROUND

Gentiopicroside (GPS) is a monomer compound of iridoid glycoside, which can inhibit the malignant behavior of lung cancer and ovarian cancer cells, but it is unknown whether it can inhibit the malignant behavior of gastric cancer cells. We hypothesized that GPS could inhibit the malignant behavior of gastric cancer cells by regulating the microRNA-34c-5p(miR-34c-5p)/X-box binding protein-1 (XBP1) axis.

AIM

To explore the effect of GPS on the proliferation, migration, and invasion of gastric cancer cells HGC-27 and the possible mechanism.

METHODS

HGC-27 cells were cultured in vitro and divided into a control group, low-, medium-, and high-dose GPS groups (6, 30, and 150 μg/mL, respectively), a miR-34c-5p group, a miR-NC group, a 150 μg/mL GPS + anti-miR-34c-5p group, and a 150 μg/mL GPS + anti-miR-NC group. Cell counting kit-8 (CCK-8) method was used to detect cell proliferation; cell migration and invasion were detected by Transwell assay; real-time quantitative polymerase chain reaction (RT-PCR) was used to detect the expression of miR-34c-5p. The expression of XBP1 protein in cells was detected by Western blot. The dual luciferase reporter gene assay was used to verify the targeted relationship between miR-34c-5p and XBP1.

RESULTS

Compared with the control group, the cell viability, the number of migrated cells, the number of invaded cells, and the expression of XBP1 protein in the GPS groups (6, 30, and 150 μg/mL) were significantly reduced (P < 0.05), but the expression of miR-34c-5p was significantly increased (P < 0.05). The cell viability, the number of migrated cells, the number of invaded cells, and the expression of XBP1 protein in the miR-34c-5p group were significantly lower than those in the control group and miR-NC group (P < 0.05). miR-34c-5p could regulate the expression of XBP1. Compared with the 150 μg/mL GPS group or 150 μg/mL GPS + anti-miR-NC group, the viability of HGC-27 cells, the number of migrated cells, the number of invaded cells, and the expression of XBP1 protein in the 150 μg/mL GPS + anti-miR-34c-5p group were significantly increased (P < 0.05).

CONCLUSION

Gentiopicroside inhibits the proliferation, migration, and invasion of gastric cancer cells via mechanisms that may be related to the regulation of the miR-34c-5p/XBP1 axis.

Gentiopicroside ameliorates ovalbumin-induced airway inflammation in a mouse model of allergic asthma via regulating SIRT1/NF-κB signaling pathway

Allergic asthma is a common airway inflammatory disorder with increasing morbidity and mortality worldwide. Gentiopicroside (GPS) is a secoiridoid glycoside compound that exhibits anti-inflammatory property. However, the effect of GPS on allergic asthma has not been reported yet. In this study, we investigated the role of GPS in a mouse model of ovalbumin (OVA)-induced allergic asthma and explored its potential mechanism. Mice were sensitized with OVA and gavaged with 20, 40, or 80 mg/kg GPS. Administration of GPS decreased lung wet-to-dry weight ratio. Histological analysis of H&E and PAS staining showed that GPS treatment alleviated inflammatory cell infiltration and goblet cell hyperplasia in lung tissue of OVA-sensitized mice. Moreover, GPS inhibited the recruitment of inflammatory cells including total cells, macrophages, eosinophils, lymphocytes and neutrophils and the secretion of T helper type 2 (Th2) cytokines (interleukin (IL)-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) of OVA-sensitized mice in a dose dependent manner. The levels of OVA-specific immunoglobulin E (IgE) and pro-inflammatory tumor necrosis factor (TNF)-α were also attenuated by GPS treatment. Interestingly, GPS upregulated the expression of silent information regulator 1 (SIRT1) while downregulated the expression of acetyl-nuclear factor kappa B (NF-κB) p65 in lung tissue of OVA-sensitized mice. Furthermore, treatment with an SIRT1 inhibitor (EX-527) partially abolished the inhibitory effect of GPS on OVA-induced airway inflammation, suggesting that the anti-inflammation of GPS might be achieved through regulating SIRT1/NF-κB p65 signaling pathway. These findings indicate that GPS might be a novel drug candidate in the treatment of allergic asthma.

Gentiopicroside ameliorates ethanol-induced gastritis via regulating MMP-10 and pERK1/2 signaling

BACKGROUND

Excessive ethanol consumption results in gastric mucosa damage, which could further develop into chronic gastritis, peptic ulcer, and gastric cancer in humans. Gentiopicroside (GPS), a major active component of Gentianae Macrophyllae radix, was reported to play a critical role in anti-inflammation. In the study, we aimed to investigate the functional role and underlying mechanism of GPS in ethanol-induced gastritis.

METHODS

A model of gastritis was created by ethanol in C57BL/6 mice. Enzyme-linked immunosorbent assay was used to determine the concentration of TNF-α, IL-1β, IL-8, and IL-10.

RESULTS

We found that GPS treatment significantly ameliorated ethanol-induced gastritis in mice, with lower production of pro-inflammatory cytokine TNF-α, IL-1β, and IL-8 and higher levels of anti-inflammatory cytokine IL-10. The anti-inflammatory effect of GPS was further confirmed in vitro in ethanol-treated human gastric mucosal GES cells. Mechanistically, we demonstrated that GPS regulated matrix metallopeptidase expression and pERK1/2 signaling. Knockdown of matrix metallopeptidase 10 (MMP-10) greatly improved cell survival and suppressed inflammatory response in ethanol-treated GES cells. Moreover, inhibition of pERK1/2 signaling using U0126 decreased the expression of MMP-10 in ethanol-induced gastritis. U0126 treatment also suppressed the expression of TNF-α, IL-1β, and IL-8, and enhanced IL-10 expression in mice gastric mucosa.

CONCLUSIONS

Taken together, our findings suggest that GPS ameliorates ethanol-induced gastritis via regulating MMP-10 and pERK1/2 signaling, which might provide a promising therapeutic drug for ethanol-induced gastritis.

Research on the Potential Mechanism of Gentiopicroside Against Gastric Cancer Based on Network Pharmacology

BACKGROUND

Gastric cancer was still one of the commonly diagnosed cancer types and the third-most common cause of cancer-related death in the world. Gentiopicroside, which is extracted from the Gentianella acuta, is commonly used in both traditional treatment and modern clinical care; therefore, its anticancer effects have been attracted more attention. However, the systematic analysis of action mechanism of Gentiopicroside on gastric cancer (GC) has not yet been carried out.

AIM

A network pharmacology-based strategy combined with molecular docking studies and in vitro validation was employed to investigate potential targets and molecular mechanism of Gentiopicroside against GC.

MATERIALS AND METHODS

Potential targets of Gentiopicroside, as well as related genes of GC, were acquired from public databases. Potential targets, and signaling pathways were determined through bioinformatic analysis, including protein-protein interaction (PPI), the Gene Ontology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, molecular docking and cell experiments were performed to further verify the above findings.

RESULTS

Our findings revealed that the anticancer activity of Gentiopicroside potentially involves 53 putative identified target genes. In addition, GO, KEGG, and network analyses revealed that these targets were associated with cell proliferation, metabolic process, and other physiological processes. Furthermore, we have proved that critical compound affected the expression of CCND1, CCNE1, p-AKT and p-P38 at protein levels. These findings provide an overview of the anticancer action of Gentiopicroside from a network perspective; meanwhile, it might also set an example for future studies of other materials used in traditional Chinese medicine (TCM).

CONCLUSION

This study comprehensively illuminated the potential targets and molecular mechanism of Gentiopicroside against GC. It also provided a promising approach to uncover the scientific basis and therapeutic mechanism of TCM treating for disease.

Hepatoprotective effect of gentiopicroside in combination with leflunomide and/or methotrexate in arthritic rats

AIMS

This study aimed to examine whether gentiopicroside (GPS) could exert hepatoprotective effects on leflunomide (LEF)- and/or methotrexate (MTX)-treated arthritic rats through anti-inflammatory and antioxidant pathways.

MAIN METHODS

We observed the external symptoms of joints, analysed serum indicators, measured haematological parameters and mRNA levels, and performed HE staining.

KEY FINDINGS

LEF and/or MTX combined with GPS ameliorated oxidative stress by increasing the mRNA levels of the antioxidant gene Nrf2, GCLC, HO-1, and NQO1, increasing the antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT), reducing the oxidant substance malondialdehyde (MDA), reducing the inflammatory response by decreasing the mRNA levels of NF-κB, tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and inhibiting the secretion of the pro-inflammatory cytokines TNFα, IL-6, IL-1β and reducing C-reactive protein (CRP), as well as alleviating the external symptoms of arthritis.

SIGNIFICANCE

These results show that GPS plays an antioxidant and anti-inflammatory role in LEF- and/or MTX-treated arthritic rats by affecting the Nrf2 and NF-κB signalling pathways, thus exerting hepatoprotective effects.

Gentiopicroside Ameliorates the Progression from Hepatic Steatosis to Fibrosis Induced by Chronic Alcohol Intake

In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol-containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.

Gentiopicroside activates the bile acid receptor Gpbar1 (TGR5) to repress NF-kappaB pathway and ameliorate diabetic nephropathy

Our previous studies indicated that the G-protein-coupled bile acid receptor, Gpbar1 (TGR5), inhibits inflammation by inhibiting the NF-κB signalling pathway, eventually attenuating diabetic nephropathy (DN). Gentiopicroside (GPS), the main active secoiridoid glycoside of Gentiana manshurica Kitagawa, has been demonstrated to inhibit inflammation in various diseases via inhibiting the inflammatory signalling pathways. However, whether GPS inhibits the NF-κB signalling pathway by activating TGR5 and regulates the pathological progression of diabetic renal fibrosis requires further investigation. In this study, we found that GPS significantly reversed the downregulation of TGR5 and inhibited the overproduction of fibronectin (FN), transforming growth factor β1 (TGF-β1), intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) in glomerular mesangial cells (GMCs) exposed to high glucose (HG). Additionally, GPS prevented the phosphorylation and degradation of IκBα, and subsequently inhibited the activation of the NF-κB signalling pathway. Further investigation found that GPS enhanced the stabilization of IκBα by promoting the interaction of β-arrestin2 with IκBα via TGR5 activation, which contributed to the inhibition of NF-κB signalling pathway. Importantly, the depletion of TGR5 blocked the inhibition of the NF-κB signalling pathway and reversed the downregulation of FN, ICAM-1, VCAM-1 and TGF-β1 by GPS in HG-induced GMCs. Moreover, GPS increased the TGR5 protein levels and promoted the interaction between IκBα and β-arrestin2, thereby inhibiting the reduction of IκBα and blocked NF-κB p65 nuclear translocation in the kidneys of STZ-induced diabetic mice. Collectively, these data suggested that GPS regulates the TGR5-β-arrestin2-NF-κB signalling pathway to prevent inflammation in the kidneys of diabetic mice, and ultimately ameliorates the pathological progression of diabetic renal fibrosis.

Metabolomic evidence for the therapeutic effect of gentiopicroside in a corticosterone-induced model of depression

BACKGROUND

Depression is a disease that seriously threatens the quality of human life. To explore the effect of gentiopicroside on depression, this study investigated the therapeutic effect of gentiopicroside on corticosterone-induced depressionin vivo and in vitro by using metabolomic methods.

METHODS

A total of 36 rats were randomly assigned to three groups: a normal group, model group (depression), and treatment group (depression + gentiopicroside). Corticosterone was administrated to induce depression-like model rats. Morris water maze test was used to validated the behavior performance. The hippocampus of rats was obtained for metabolomic detection. Metabolites that were differentially expressed between the groups were extracted for Heatmap, Go, and pathway enrichment analyses. Finally, neuronal cells were cultured and examined to validated the effect of gentiopicroside.

RESULTS

Corticosterone injured rats learning capacity, and decreased the levels of 5-HT, and reversed by gentiopicroside delivery. Metabolites obtained from the hippocampus of rats in the three groups were subjected to a principal component analysis (PCA). Go and pathway enrichment analyses revealed the involvement of sphingolipid metabolism et al. Gentiopicroside could inhibit apoptosis caused by corticosterone, and also decrease neuronal cell proliferation and BDNF levels in vitro. Arachidonic acid (ARA) reversed the protective effect of gentiopicroside on neuronal cells.

CONCLUSION

These findings suggest that gentiopicroside reduces apoptosis and increases the proliferation of hippocampus cells in depressed animals by regulating metabolites. Moreover, our study provides a new basis for the clinical treatment of depression and demonstrates the potential efficacy of gentiopicroside in this area of pathology.

Gentiopicroside isolated from Gentiana scabra Bge. inhibits adipogenesis in 3T3-L1 cells and reduces body weight in diet-induced obese mice

Gentiopicroside is a major active component of the Gentiana scabra Bge., which is commonly used as herbal medicine for the treatment of inflammation in Asia. Gentiopicroside significantly down-regulated expression of key adipogenic transcription factors (PPARγ, C/EBPα, SREBP-1c) and dose-dependently inhibited the lipid uptake-related gene (LPL), fatty acid transport-related gene (FABP4) and triglyceride (TG) synthesis-related gene (DGAT2), as well as fatty acid synthesis-related genes (FAS, SCD1), which resulted in reduced intracellular lipid droplet accumulation and TG content in 3T3-L1 cells. Gentiopicroside also down-regulated expression of inflammatory cytokine genes (NFκB1, TNFα, IL6) compared with vehicle. Oral administration of gentiopicroside (50 mg/kg) in mice fed with high-fat diet for 12 weeks resulted in reduced body weight and visceral fat mass compared with the control group. Overall, the results of this study showed that gentiopicroside had positive anti-obesity effects by regulating the expression of adipogenesis/lipogenesis-related genes and inflammatory genes in 3T3-L1, and that it effectively reduced body weight and visceral fat mass in vivo.

[Antidermatophyte Activity of the Gentiopicroside-Rich n-Butanol Fraction from Gentiana siphonantha Maxim. Root on a Guinea Pig Model of Dermatophytosis]

BACKGROUND

Gentiana siphonantha Maxim. is a traditional medicine for the treatment of rheumarthritis, icterepatitis, pain and hypertension; it is rich in gentiopicroside with anti-inflammatory, antibacterial, and free radical-scavenging activities. This study was to evaluate the antidermatophyte activity of G. siphonantha on a guinea pig model in vitro and in vivo. Material andMethods: The antidermatophyte activities of 10 plants were tested by the broth microdilution method. Fractions and an extract of G. siphonantha were tested against Trichophyton mentagrophytes by the disc diffusion method. The morphological changes of T. mentagrophytes were observed. Component analysis of the n-butanol (n-BuOH) fraction was made by HPLC. Finally, the antifungal activity in an in vivo guinea pig model of dermatophytosis was examined.

RESULTS

G. siphonantha had strong antidermatophyte activity with MIC50 values of 32-64 μg/mL. The n-BuOH fraction of G. siphonantha showed the most potent activity compared to the other fractions. After being exposed to the n-BuOH fraction at 80 and 160 μg/mL, the hyphae were distorted and collapsed. Gentiopicroside is the main active ingredient in the n-BuOH fraction of G. siphonantha. The lesion scores of the guinea pig model of dermatophytosis significantly declined in the 10% and 30% extract and positive control groups in comparison with the untreated control group. Periodic acid-Schiff and hematoxylin/eosin staining displayed similar results.

CONCLUSION

The n-BuOH fraction of G. siphonantha demonstrated antidermatophyte efficacy in experimental dermatophytosis.

Gentiopicroside Ameliorates Diabetic Peripheral Neuropathy by Modulating PPAR- Γ/AMPK/ACC Signaling Pathway

BACKGROUND/AIMS

Gentiopicroside is promising as an important secoiridoid compound against pain. The present study aimed to investigate the analgesic effect and the probable mechanism of Gentiopicroside on Diabetic Peripheral Neuropathy (DPN), and to figure out the association among Gentiopicroside, dyslipidemia and PPAR- γ/AMPK/ACC signaling pathway.

METHODS

DPN rat models were established by streptozotocin and RSC96 cells were cultured. Hot, cold and mechanical tactile allodynia were conducted. Blood lipids, nerve blood flow, Motor Nerve Conduction Velocity (MNCV) and Sensory Nerve Conduction Velocity (SNCV) were detected. Gene and protein expression of PPAR- γ/AMPK/ACC pathway was analyzed by reverse transcription-quan titative polymerase chain reaction (RT-qPCR) and Westernblot. Besides, PPAR-γ antagonist GW9662 and agonist rosiglitazone, AMPK antagonist compound C and activator AICAR as well as ACC inhibitor TOFA were used to further confirm the relationship between PPAR-γ and AMPK.

RESULTS

The results demonstrated that Gentiopicroside markedly ameliorated hyperalgesia with prolonged paw withdrawal latency to heat and cold stimuli and fewer responses to mechanical allodynia compared with DPN model group. Gentiopicroside regulated dyslipidemia, enhanced nerve blood flow and improved MNCV as well as SNCV. Gentiopicroside suppressed ACC expression through the activation of AMPK and PPAR-γ mediated the activation of AMPK and subsequent inhibition of ACC expression.

CONCLUSION

In conclusion, the present study demon strated that Gentiopicroside exerted nerve-protective effect and attenuated experimental DPN by restoring dyslipidmia and improved nerve blood flow through regulating PPAR-γ/AMPK/ACC signal pathway. These results provided a promising potential treatment of DPN.

Gentiopicroside abrogates lipopolysaccharide-induced depressive-like behavior in mice through tryptophan-degrading pathway

Targeting neuroinflammatory disturbances has been acknowledged as a potential strategy for treatment of depressive disorder in humans. Over-activation of tryptophan-degrading pathway by pro-inflammatory cytokines resulted in N-methyl-d-aspartate (NMDA)-mediated excitotoxicity, which is implicated in pathophysiology of depression. Gentiopicroside (Gent) has powerful anti-inflammatory property and exhibits promising antidepressant effect in an animal model of pain/depression dyad by down-regulating GluN2B-containing NMDA receptors. Therefore, the present study aimed to investigate the ability of Gent to abolish depressive-like behavior induced by lipopolysaccharide (LPS) in mice. Acute administration of LPS (0.5 mg/kg, i.p.) increased immobility time in both forced swimming test (FST) and tail suspension test (TST) without affecting spontaneous locomotor activity, indicative of depressive-like behavior. Gent (50 mg/kg, i.p.) administered once a day for three consecutive days prevented the development of depressive-like behavior induced by LPS. The antidepressant-like effect was paralleled with restoration of LPS-induced alterations in brain inflammatory mediators (i.e. IL-1β and TNF-α). In addition, Gent prevented over-activation of indoleamine 2,3-double oxygen enzyme (IDO) and recovered GluN2B subunit expression in the PFC challenged by LPS. In conclusion, our results suggested that Gent pretreatment provided protection against LPS-induced depressive-like behavior and the effect appeared to be demonstrated, at least partially, by blocking various steps of tryptophan-degrading pathway.

Gentiopicroside inhibits RANKL-induced osteoclastogenesis by regulating NF-κB and JNK signaling pathways

Gentiopicroside, a main active component from the traditional Chinese herb medicine Gentiana manshurica Kitag, has been shown to possess anti-arthritis effect. However, the molecular mechanism of gentiopicroside on the osteoclast formation remains unclear. The present study was designed to investigate the effects and mechanisms of gentiopicroside on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. The results showed that pre-treatment with gentiopicroside significantly inhibited RANKL-induced osteoclast formation from mouse bone marrow macrophages (BMMs). In addition, we observed that gentiopicroside efficiently suppressed osteoclastogenesis-related marker genes expression in RANKL-stimulated BMMs. Mechanistically, gentiopicroside suppressed RANKL-induced the activation of JNK and NF-κB signaling pathways in BMMs. Taken together, the present study demonstrated that gentiopicroside inhibits RANKL-induced osteoclastogenesis through the inactivation of JNK and NF-κB signaling pathways. Thus, gentiopicroside may be a promising agent for the treatment of osteoporosis.

Medicinal, biological and phytochemical properties of Gentiana species

Gentiana, a cosmopolitan and important genus of the Gentianaceae family, comprises 400 species distributed among the world. Based on the studies of Iranian traditional medicine texts, there are some promising bioactivities for this genus that is unknown in modern medicine and some of them are still the basis of new remedies. In traditional medicine texts, Gentiana's different exclusive forms of preparations are effective for treatment of some disorders such as menstrual over-bleeding, conjunctivitis, vitiligo, animals venom poisoning, injuries, infected wounds, pain and swelling of liver, spleen, stomach and sprains of muscles. There are some activities that are the same in traditional and modern medicine such as anti-inflammatory, hepatoprotective and diuretic effects. Phytochemical investigations on the title genus have led to characterization many secondary metabolites. Secoiridoidal and iridoid glycosides such as gentiopicroside, xanthones, monoterpene alkaloid; polyphenol and flavones are the constituents that have been shown the pharmacological activities in different gentian species. This article studies the Gentiana according to the Iranian traditional and modern medicine.

Iridoid glycosides from the flowers of Gentiana macrophylla Pall. ameliorate collagen-induced arthritis in rats

BACKGROUND

The flowers of Gentiana macrophylla have been usually applied to cure the joint inflammation and rheumatoid arthritis in Traditional Chinese Medicine.

HYPOTHESIS/PURPOSE

This work aimed to investigate the anti-rheumatoid arthritic effect and possible mechanism of iridoid glycosides from G. macrophylla (GMI) using an animal model of collagen-induced rheumatoid arthritis (CIA) in rats.

STUDY DESIGN

All rats were randomly divided into five groups: normal control, CIA, dexamethasone, 15mg/kg and 30mg/kg GMI.

METHODS

CIA was induced (day 0) in male Sprague-Dawley rats by intradermal injection of complete Bovine CII at the base of the tail. Dexamethasone was chosen as the positive drug. The administration of different drugs started from day 1 and continued for 28 days. Paw swelling, arthritis score and histopathological changes were examined to assess the severity of arthritis. In addition, the serum levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions in joint synovial tissues were detected.

RESULTS

GMI reduced paw edema, arthritis scores and the index of spleen and thymus from day 7 to 21 after CIA compared with those in the CIA group. Our data also demonstrated that GMI inhibited pro-inflammatory cytokines such as TNF-α, IL-1β and IL-6, regulated the expression of iNOS and COX-2 compared with those in the CIA group. We also obtained four major components from GMI, identified as loganic acid, swertamarin, gentiopicroside and sweroside, and the contents of them were also calculated respectively.

CONCLUSION

Taken together, our results shed light on the therapeutic efficacy of GMI in rats rheumatoid arthritis model by reducing the levels of IL-1β, IL-6 and TNF-α in serum as well as down-regulating the levels of iNOS and COX-2. Therefore, GMI may be an effective therapy for the treatment of rheumatoid arthritis.

Gentiopicroside prevents interleukin-1 beta induced inflammation response in rat articular chondrocyte

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, Gentiana macrophylla Pall have been prescribed for the treatment of pain and inflammatory conditions. In addition, it is a common Tibetan medicinal herb used for the treatment of tonsillitis, urticaria, and rheumatoid arthritis (RA), while the flowers of G. macrophylla Pall have been traditionally treated as an anti-inflammatory agent to clear heat in Mongolian medicine. The secoiridoid glycosides and their derivatives are the primary active components of G. macrophylla and have been demonstrated to be effective as anti-inflammatory agents.

MATERIALS AND METHODS

Solvent extraction and D101 macroporous resin columns were employed to concentratethe gentiopicroside. Gentiopicroside cytotoxicity was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; the toxicity of gentiopicroside in chondrocytes was reconfirmed using Hoechst staining. Western blotting, reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry were utilized to explore the protective effects and mechanisms of gentiopicroside prevents interleukin-1 beta induced inflammation response in rat articular chondrocyte.

RESULTS

The MTT assay demonstrated that 50, 500, and 1,500 μg/mL of gentiopicroside exhibited no significant toxicity to chondrocytes (P>0.05) after 24h. Using immunohistochemistry, ELISA, RT-PCR, Western blot method to explore the protective effect and mechanism of gentiopicroside on chondrocytes induced by IL-1β. The results showed some pathways of IL-1β signal transduction were inhibited by gentiopicroside in rat chondrocytes: p38, ERK and JNK. Meanwhile, gentiopicroside showed inhibition in the IL-1β-induced release of MMPs while increasing Collagen type II expression.

CONCLUSIONS

The current study demonstrated that gentiopicroside exhibited a potent protective effect on IL-1β induced inflammation response in rat articular chondrocyte. Thus, gentiopicroside could be a potential therapeutic strategy for treatment of OA.

Attenuation of stress-induced gastrointestinal motility disorder by gentiopicroside, from Gentiana macrophylla Pall

AIM

The current study was designed to explore the mechanism of the prokinetic activity of Gentiopicroside (Ge), from Gentiana macrophylla Pall which is widely used to strengthen gastric motility in clinic.

METHODS

Gastrointestinal motility disorder rats were induced by stress stimulation and the rats were treated with Ge. The functions of gastric emptying and intestinal propelling were measured after blood was obtained to assay the levels of plasmatic motilin (MTL), vasoactive intestinal peptide (VIP), somatostatin (SST), gastrin (GAS), neurotensin (NT) and substance of P (SP). The expressions of MTL receptor (MTLR), VIP receptor 2 (VIPR2) and SST receptor 2 (SSTR2) were measured also. In addition, an isolated guinea pig ileum was applied to evaluate the influences of Ge on M-R, H1-R, 5-HT4-R and D-R in vitro.

RESULTS

Ge increased gastric emptying and intestinal propelling obviously. It also decreased the level of SST and increased GAS in plasma significantly. Moreover, it promoted the expressions of MTLR in gastric antrum, duodenum, jejunum and ileum, and restrained the expression of VIPR2 in duodenum. Piboserod and loratadine had no obvious restrain to Ge' exciting ileum effect and Ge also didn't affect dopamine paralyzing ileum. However, Ge failed to improve the hypofunction of guinea pigs ileums pre-treated with atropine sulfate.

CONCLUSION

The mechanisms of Ge' prokinetic effect were associated with modulating the levels of SST and GAS in plasma, raising the expressions of MTLR in gastric antrum, duodenum, ileum and jejunum, reducing the expression of VIPR2 in duodenum and activating M-R.

New analytical method for the study of the metabolism of gentiopicroside in rats after oral administration by LC-TOF-MS following picolinoyl derivatization

The metabolism of gentiopicroside (GPS) in vivo was studied for the first time by LC-MS following picolinoyl derivatization. Incubation of erythrocentaurin, one of the main in vitro metabolites of GPS by intestinal bacteria, with liver microsome indicated that GPS might be metabolized to a final metabolite 3,4-dihydro-5-(hydroxymethyl)isochroman-1-one (HMIO) in vivo. After hydrolysis with sulfatase, HMIO was successfully detected in rat plasma after oral administration of GPS by LC-MS following picolinoyl derivatization. 4-Methoxyphenyl methanol was used as an internal standard to quantify HMIO in rat plasma. A metabolic pathway of GPS in rats is proposed. The monoterpene compound GPS was found to be metabolized to dihydroisocoumarin, which may be responsible for the pharmacological effect of GPS.

Comparative analysis among three Taiwan-specific Gentiana species and Chinese medicinal plant Gentiana scabra

BACKGROUND

The root of Gentiana scabra is commonly known as Longdan in Chinese herbal medicines and has been used in the treatment of inflammation, anorexia, indigestion and gastric infections for over 2000 years. High market demand had made G. scabra (GS) plants not to be the only source of Longdan in China, other Gentiana spp., G. triflora, G. manshurica and G. rigescens, were also recognized as Longdan in China now.

RESULTS

In this study, we identified three Taiwan-specific Gentiana spp., G. davidii var. formosana (GDF) and G. arisanensis (GA) and G. scabrida var. punctulata (GSP) that are phylogenetically different from GS (main source of Longdan). However, the active compounds of Longdan, gentiopicroside and swertiamari, were found in GSP and GDF showed higher antioxidant ability and free radical scavenging activities than Chinese Longdan. This discovery might explore the medicinal potential of GDF. Meanwhile, another Taiwan-specific Gentiana spp., GSP, was found to have the strongest antioxidant ability and free radical scavenging activities which might suggest a possible use of GSP as a source of natural antioxidant agents for industrial purpose.

CONCLUSIONS

The finding of this study indicated that ITS analysis can be used to identify Taiwan-specific Gentiana spp. Also the Taiwan-specific Gentiana spp. which has strongest antioxidant and free radical scavenging activities among others could be a better choice for industrial purpose.